 Viral vectors are being used to treat a wide range of diseases, including metabolic, cardiovascular, muscular, hematological, ophthalmological, and infectious diseases, as well as different types of cancer. Immunotherapies and gene silencing techniques are also being explored with viral vectors, providing both prohibitive and therapeutic options. Preclinical and clinical trials have shown promising results, leading to the approval of several viral vector-based drugs worldwide. This article was authored by Kenneth Lundstrom.